Looks like a nice list of upgrades.
You may want to close the inner door openings, remove the plastic moisture barrier since you are treating the doors, for even better midbass response.
There are only 2 big holes in the front doors, the small one can be just covered with the same dampening material, the big one, you can cover it in many different ways depending on the material you choose.
Galvanized roof flash sheet metal or aluminum is the cheapest, ABS Plastic or plexiglass is another one 1/4" thick, and if you want to get fancy rivet nuts after drilling and touch painting the drilled areas. SS sheet metal screws if not using rivet nuts.
Gaps filled with closed cell foam, camper seal window seal with good adhesive, the bottom part of the the big long opening has a huge gap, maybe non hardening clay or caulk rope will be needed to fill the gap as I did mine. Or many layers of CCF.
Cover inner door edges and cover can simply be closed with the same dampening material or aluminum tape. Treat one side of the cover with the same 30-35% coverage of Knu Kol, in or out, no need to do both. leave space for cable and wire runs, a bit of CCF and duct tape around the cable, if the metal is sharp will help to seal and protect the cables.
The main thing is easier access to the motor or window assemblies in case service is needed.
If you decide to go with a layer of CCF and MLV (closed cell foam and Mass loaded vinyl)
there is no need to close the openings with sheet metal, the velcro and flexibility of the 1/8"CCF and MLV will mold to the areas and provide equal or similar function, according to the SDS site and direct response I had from the owner, the benefit of the MLV is less noise while driving but that is just another level door deadening and it is hard and time consuming with a lot of improvisation involved getting the door panels to snap properly in place, I went through it with my rear doors only.
If you have any other questions feel free to post them, good luck and I am glad I was able to help, other members also gave great information and contribution, and I hope others can benefit from the info from this thread.
Here is a recent video and if possible watch video on the link he recommends, this guy makes great videos, worth watching.
Usually the the adapters supplied by the after market speaker manufacturer are not quite thick, leaving a big gap between the door panel and the speaker, a 3/4" thick spacer will work for our doors, closing the gap or reducing most of it to keep sound from staying between the panel and the inner door. The F.A.S.T. rings are not needed for our doors, although some may still want to pay the high tag and use them.
If you decide not to make your own baffle spacers and use the JBL ones, by all means, the F.A.S.T. rings will be worth the high price tag, since ABS, or HDPE plastic is expensive